Passport Office workers will strike for five weeks as a dispute over jobs, pay and conditions escalates.
The action will take place from April 3 to May 5 in England, Scotland and Wales and will see more than 1,000 members of the Public and Commercial Services (PCS) union working in Passport Offices take action.
Those working in Durham, Glasgow, Liverpool, London, Newport, Peterborough and Southport will walk out from April 3 to May 5.
However, those in Belfast will strike from April 7 to May 5.
Passport Office strikes could impact delivery of passports ahead of summer
The union said the action was a “significant escalation” of its long-running dispute, warning it was likely to have a “significant impact” on the delivery of passports as the summer approaches.
PCS general secretary Mark Serwotka said: “This escalation of our action has come about because, in sharp contrast with other parts of the public sector, ministers have failed to hold any meaningful talks with us, despite two massive strikes and sustained, targeted action lasting six months.
“Their approach is further evidence they’re treating their own workforce worse than anyone else. They’ve had six months to resolve this dispute but for six months have refused to improve their 2% imposed pay rise, and failed to address our members’ other issues of concern.
“They seem to think if they ignore our members, they’ll go away. But how can our members ignore the cost-of-living crisis when 40,000 civil servants are using foodbanks and 45,000 of them are claiming the benefits they administer themselves?
“It’s a national scandal and a stain on this government’s reputation that so many of its own workforce are living in poverty.”